Originally Posted by
john34683
at first (when we were having issues getting to to start) the MAP stayed at 11 or 12, we finally got it to start and it slowly started to creep up to 20 (even if the motor was not running). After we fixed some of the grounds it went up to 100 and stayed there while the car idled, under part throttle and even when we turned the car off.
It
should read 100 when the car is off. 100 = atmosphere (I assume you know this already though)
I believe it should read around low to mid 20s on a stock 420a at idle (assuming the rings are not wasted and the valve seals are good) - that was what I had back on my stock block.